1. Field of the Invention
The present invention relates to the field of handlebars for power vehicles such as two wheeled vehicles and all terrain vehicles, and in particular to handlebars for off road motorcycles, dirt bikes, all terrain vehicles and jet skis.
2. Description of the Prior Art
Conventional handlebars for off road motorcycles and dirt bikes traditionally comprise a bent bar with a handle at each end. A front plan view of common prior art handlebars for motorcycles is illustrated in FIG. 1. The common prior art handlebars 100 comprise a bent bar 110, having a central section 120 and oppositely disposed end sections 130 and 140 which are mirror images of one another. The diameter "d" of the tubing for the bent bar 110 is traditionally of uniform diameter for the entire length of the bar. In general, the preferred diameter is 7/8 inch because this provides the end sections 130 and 140 with the proper amount of thickness so that a handle member preferably made of polyvinyl or rubber and having a thickness of approximately 1/8 to 1/4 inch can be fitted over a portion of each end section.
While the thickness of approximately 7/8 inch for the diameter provides an ideal thickness to facilitate the gripping member or handle at either end, it provides the middle section 120 and bent sections 132 and 142 with a thin member for absorbing the stresses, strains and shocks imparted to the handlebars 100 from off road or dirt bike riding. In order to strengthen the handlebars, the prior art design includes a crossbar 150 which is attached to the handlebars 100 at the locations of the intersection of the end section 130 with bent section 132 and the intersection of the end section 140 with bent section 142. There are two conventional methods by which the crossbar 150 is attached. In one method, the crossbar 150 is welded in place. In the second method, the crossbar 150 is clamped in place with a pair of clamps that are tightened with bolts.
In operation, the handlebars 100 are attached to the motorcycle, dirt bike, all terrain vehicle or jet ski along the length of the middle section 120 and usually at two spaced apart locations, and such that the crossbar 150 is facing the rider on the off road motorcycle, dirt bike or other vehicle. The 7/8 inch middle section is usually not of sufficient strength to withstand the impact of heavy loads, and the purpose of the crossbar 150 is to prevent the handlebars 100 from buckling if the off road motorcycle or dirt bike should bump into something or crash to the ground. In fact, what happens is that the crossbar 150 and attachment to the bent tube 110 causes a permanent compression set to occur in the bent tubing 110 in the event of an impact. In addition, the crossbar 150 provides no added benefit when steering the off road motorcycle or dirt bike, and therefore the crossbar 150 in fact reinforces the handlebars 100 in only the verticle direction but not in the horizontal direction.
Therefore, the major disadvantage of prior art handlebars is that they require a crossbar for strength. However because the crossbar provides rigid support at its attachment points to the bent tube, it forces stress concentrations there, which tends to take a permanent set in falls. The crossbar also constrains any movement that would soften shock loads to the grips which are placed over the ends of the handlebars.
There is a significant need for an improved configuration for handlebars which provides greater strength, improved shock absorption, and improved steering capability.